1. Field of the Invention
The present invention relates to a seedlike substance making apparatus which continuously encloses cultured tissues (enclosures) such as adventive embryos into capsules in an aseptic condition.
2. Description of the Prior Art
Among the techniques that disclose the means for making enclosures are Japanese Patent Application Laid-Open Specifications Nos. 62-266137, 63-197530, 3-4706 and 3-127920.
As represented by "the method of making artificial seeds" in Japanese Patent Application Laid-Open Specification No. 3-127920, these techniques disclose a means that disperses and encloses cultured tissues such as adventive embryos into a gelling agent (a material capable of gelling according to chemical reactions), supplies liquid droplets of the cultured tissues through a small hole into a hardener, and sphericalizes the liquid droplets during the process of falling by the application of surface tension. Another means disclosed by these references is to continuously extrude the cultured tissues from a nozzle into a hardener to form them into long string-like shapes and then cut them into appropriate lengths.
The technique of Japanese Patent Application Laid-Open Specification No. 63-197530 moves an end of a hose connected to a sol supply tank in a planetary motion by using a planetary gear to drop sol--which has a number of enclosed tissues dispersed in a coating agent--from the end of the hose into a hardening tank below.
A technique of Japanese Patent Application Laid-Open Specification No. 62-266137 uses a centrifugal force to make the liquid droplets.
Of the means disclosed in the Japanese Patent Application Laid-Open Specification No. 3-127920, the former has a disadvantage that it is difficult to uniformly disperse a number of enclosed tissue elements in a coating agent. The droplets of coating material supplied into the hardening agent include those droplets that contain the enclosed tissue pieces and those that do not. These droplets of coating material are mixed, making it necessary to provide a process for sorting out those coating material droplets containing the enclosures from those that do not.
The extrusion means has a disadvantage in that is extremely difficult to determine the position at which to cut the string-like coating materials into blocks and that therefore, the number of cultured tissue pieces enclosed in the cut coating blocks is variable.
With the techniques of Japanese Patent Application Laid-Open Specifications Nos. 63-197530 and 62-266137, too, it is difficult to uniformly disperse a number of enclosured tissue pieces.
The cultured tissues, the enclosures, are valuable. When the number of enclosures is one, there is no waste. When there are more than one tissue enclosures per encapsulation, the extra tissues may be wasted.
The coating blocks containing no enclosure must be removed by a troublesome selection process.
With these methods, it is not possible to make arbitrary changes to the size of the coating materials and the number of enclosures.
With a seed coating apparatus (Japanese Utility Model Application Laid-Open Specification No. 5-7018) which coats an enclosure with a film of the coating material, it is possible to arbitrarily change the diameter of the encapsulating coating material and the number of enclosures contained therein. To change the capsule diameter, however, requires adjusting by manual operation, the amount of coating material that is delivered. This method, therefore, cannot be applied to an apparatus for making a seedlike substance installed in an aseptic room.
The object of this invention is to solve the above-mentioned problems and to provide an apparatus for making a seedlike substance comprising encapsulated tissue piece(s) enclosed in a coating material, which can insert an arbitrary number of enclosured tissue pieces into a coating block and to enable arbitrary changes to the size of capsule diameter and to the number of enclosures to be made.